Quick release personnel transfer device between boat and platform

ABSTRACT

This disclosure is directed to a quick release device between a personnel boat and an offshore rig employing a magnetic coupling of the permanent type which resists axial separation but permits shear or slide separation.

United States Patent Inventor Appl. No.

Filed Patented Assignee Douglas W. Moore Metairie, La.

Mar. 2, 1970 Sept. 14, 1971 Compressors Automation Controls, Inc. Marrero, La.

QUICK RELEASE PERSONNEL TRANSFER DEVICE BETWEEN BOAT AND PLATFORM 3 Claims, 3 Drawing Figs.

US. Cl

[50] Field of Search 182/129, 127,107, 82, 93

[56] References Cited FOREIGN PATENTS 745,837 3/1956 Great Britain 182/107 Primary Examiner- Reinaldo P. Machado AttorneyWilkinson, Mawhinney and Theibault ABSTRACT: This disclosure is directed to a quick release device between a personnel boat and an offshore rig employing a magnetic coupling of the permanent type which resists axial separation but permits shear or slide separation.

PATENIEH SEP] 4 I9?! IN VEN TOR. L UGLAs w. MOORE mMMwQM knQw An object of the present invention is the provision of a positive-coupling personnel ladder device for transferring men from an offshore drilling rig to a personnel boat or vice versa,

which will maintain the boat and rig in contact through a ladder or ramp which, while being subject to wave motion and the usual relative movement between a boat and a dock, will maintain a positive contact therebetween and whichmay permit quick separation between the boat and dock by exertion of a shear force between the boat and dock as by speeding up the boat and causing the coupling means to slide in shear and separate without having to have a line tender release a rope or cable coupling therebetween.

A further object of the present invention is the joining of a personnel transfer device such as a ladder or gangway to a boat and maintaining this positive contact by either permanent magnet(s) or electromagnets where separation along the axis of magnetic couple is, by nature of the coupling, extremely difficult to break but more easily may be broken in shear or at right angles to the couple.

In the offshore drilling industry, personnel are moved between the rig and the beach by boats; and all rigs have some form of personnel transfer device for moving men between the rig and boat, ranging from a swinging line to pivoted gangways to personnel baskets operated from cranes or winches on the rig but a quick couple up and release device which will maintain positive contact between the rig and boat without rope or ordinary mechanical attachments has not been available. Further, rigid mechanical or rope connections can in rough weather be a threat to the integrity of the boat and also be difficult to achieve mating; an advantage of the coupling proposed is that it permits sliding under excessive shear forces without breaking the connection, thus serving a clutch function. Also, connection can be made anywhere on the boat deck or plate and be subsequently moved anywhere on the deck or plate.

With the foregoing and other objects in view the invention will be more fully described hereinafter and more particularly pointed out in the appended claims.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the different views:

FIG. 1 is a fragmentary perspective view of a personnel boat connected to an offshore rig through a ladder ramp constructed in accordance with the present invention.

FIG. 2 is a fragmentary side elevational view of a personnel boat and ramp coupled in accordance with the present invention.

FIG. 3 is a view similar to FIG. 2 showing the boat backing away and breaking the coupling connection.

Referring now to FIG. 1, 10 designates an offshore rig which has personnel it wishes to send ashore. Pivotally connected to the rig is a personnel gangway 11, the pivot being for vertical movement, lateral movement, and pitch, yaw and roll, to accommodate for tidal and weather conditions which would cause a vessel or boat to move to the platform 10 above. A personnel boat 12 is equipped with a fairly smooth steel deck or plate which receives the free end 14 of the personnel gangway.

A c'oupling between the free end 14 of the personnel gangway 11 and the platform 13 on boat 12 may be one large permanent magnet 15, and 16 being a steel deck or plate. The magnet 15 is secured to the free end 14 of gangway 11.

The magnet 15, should be of either the ceramic or alnico type (alnico 8 for example) when permanent magnets are employed or any strong magnet material. When electromagnets are employed the member 16 will be the coil and the member 15 will have high magnetic permeability, although these can be interchanged.

When the boat approaches the rig from the Lee, stern toward the rig during transfer of personnel should someone fall off gangway 11 into the water they would be immediately drawn into the screws of the boat and be cut up so a positive connection is vital.

The permanent magnet which is separable by a force in shear or at right angles to the axis of magnetic couple are preferable.

What I claim is:

1. For use between a marine platform and a boat a quick release personnel transfer device comprising a personnel transfer ladder adapted to be connected to the marine platform at its upper end, a boat ladder support adapted to be secured to the deck of a boat and to receive and support the free end of said ladder, and magnetic coupling means, one element of which is secured to the free end of said ladder and the other element of which is secured to said boat ladder support for magnetic coupling therewith.

2. A quick release personnel transfer device as claimed in claim 1 wherein said magnetic coupling means are one smooth faced permanent magnetic element and a steel or iron plate which may be separated only by shear sliding transfer on across the face of the other.

3. A quick release personnel transfer device as claimed in claim 1 wherein the magnetic coupling means is an electromagnet. 

1. For use between a marine platform and a boat a quick release personnel transfer device comprising a personnel transfer ladder adapted to be connected to the marine platform at its upper end, a boat ladder support adapted to be secured to the deck of a boat and to receive and support the free end of said ladder, and magnetic coupling means, one element of which is secured to the free end of said ladder and the other element of which is secured to said boat ladder support for magnetic coupling therewith.
 2. A quick release personnel transfer device as claimed in claim 1 wherein said magnetic coupling means are one smooth faced permanent magnetic element and a steel or iron plate which may be separated only by shear sliding transfer on across the face of the other.
 3. A quick release personnel transfer device as claimed in claim 1 wherein the magnetic coupling means is an electromagnet. 